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 * Licensed to the Apache Software Foundation (ASF) under one   *
 * or more contributor license agreements.  See the NOTICE file *
 * distributed with this work for additional information        *
 * regarding copyright ownership.  The ASF licenses this file   *
 * to you under the Apache License, Version 2.0 (the            *
 * "License"); you may not use this file except in compliance   *
 * with the License.  You may obtain a copy of the License at   *
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 * Unless required by applicable law or agreed to in writing,   *
 * software distributed under the License is distributed on an  *
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY       *
 * KIND, either express or implied.  See the License for the    *
 * specific language governing permissions and limitations      *
 * under the License.                                           *
 ****************************************************************/

package org.apache.james.protocols.pop3.core;

import org.apache.james.protocols.api.Request;
import org.apache.james.protocols.api.Response;
import org.apache.james.protocols.api.handler.UnknownCommandHandler;
import org.apache.james.protocols.pop3.POP3Response;
import org.apache.james.protocols.pop3.POP3Session;
import org.apache.james.util.MDCBuilder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Default command handler for handling unknown commands
 */
public class UnknownCmdHandler extends UnknownCommandHandler<POP3Session> {
    private static final Logger LOGGER = LoggerFactory.getLogger(UnknownCmdHandler.class);

    /**
     * Handler method called upon receipt of an unrecognized command. Returns an
     * error response and logs the command.
     */
    @Override
    public Response onCommand(POP3Session session, Request request) {
        MDCBuilder.withMdc(
            MDCBuilder.create()
                .addToContext(MDCBuilder.ACTION, request.getCommand())
                .addToContext(MDCConstants.withSession(session))
                .addToContext(MDCConstants.forRequest(request)),
            () -> LOGGER.info("Unknown command received"));
        return POP3Response.ERR;
    }
}
